Acetyl%25252520cysteine

# Acetylcysteine ## Overview Acetylcysteine is a mucolytic agent (via sulfhydryl group cleavage of disulfide bonds in mucus) and a glutathione precursor used as an antidote for acetaminophen toxicity. ## Primary Indications * **Acetaminophen toxicity:** Prevention or treatment of hepatotoxicity. * **Mucolytic therapy:** Adjunct in bronchopulmonary diseases (e.g., CF, chronic bronchitis). * **Radiocontrast-induced nephropathy:** Prevention (clinical efficacy remains controversial). ## Adult Dosing * **Acetaminophen Toxicity (IV Protocol):** * Loading: 150 mg/kg in 200 mL D5W over 60 minutes. * Second Dose: 50 mg/kg in 500 mL D5W over 4 hours. * Third Dose: 100 mg/kg in 1000 mL D5W over 16 hours. * **Acetaminophen Toxicity (Oral Protocol):** 140 mg/kg loading dose, followed by 70 mg/kg every 4 hours for 17 doses (total 18 doses). * **Inhalation (Mucolytic):** 1–10 mL of 20% solution or 2–20 mL of 10% solution via nebulizer every 2–6 hours. ## Pediatric Dosing * **Acetaminophen Toxicity:** Dosing follows the same 3-bag IV protocol as adults, adjusted by weight. Ensure weight-based fluid volume reduction to prevent hyponatremia/fluid overload. * **Inhalation (Mucolytic):** 3–5 mL of 20% solution or 6–10 mL of 10% solution via nebulizer 3–4 times daily. ## Dose Adjustments * **Renal/Hepatic:** No specific dose adjustment for mucolytic use. For IV acetaminophen toxicity, maintain standard weight-based dosing; adjust fluid volume based on age/weight to avoid fluid overload. ## Contraindications * **Hypersensitivity:** Known history of anaphylactoid reaction to acetylcysteine. * **Oral/Nebulized:** Use caution in patients with active asthma or severe bronchospasm (may cause bronchoconstriction). ## Adverse Effects * **IV:** Anaphylactoid reactions (flushing, urticaria, angioedema, hypotension), nausea, vomiting. * **Inhalation:** Bronchospasm, rhinorrhea, stomatitis, unpleasant odor (sulfur). ## Key Drug Interactions * **Activated Charcoal:** May adsorb acetylcysteine. If charcoal was administered, prioritize lavage or wait 1–2 hours before oral acetylcysteine; if necessary, administer both and adjust total dose if charcoal significantly reduces absorption. * **Nitroglycerin:** High-dose IV acetylcysteine may potentiate nitrate-induced vasodilation and hypotension. ## Monitoring * **Acetaminophen Toxicity:** Acetaminophen levels (to determine necessity of treatment); AST/ALT, bilirubin, INR, and creatinine (baseline and daily). * **IV Infusion:** Monitor for anaphylactoid reactions throughout infusion; hold infusion if severe reaction occurs and manage symptomatically (antihistamines, corticosteroids, epinephrine). ## Clinical Pearls * **IV Protocol:** Follow the FDA-approved 20-hour protocol; if patient remains symptomatic or liver enzymes are rising, continue infusion at the 100 mg/kg/16hr rate. * **Nebulized Administration:** Always use with a bronchodilator (e.g., albuterol) to prevent drug-induced bronchospasm. * **Odor:** Warn patients that the medication smells like rotten eggs; this is normal. * **Stability:** IV vials are stable after opening for 24 hours under refrigeration. *** **Educational Disclaimer:** This information is for educational purposes only. Always verify doses, contraindications, and drug compatibility against institutional protocols, current package inserts, or clinical decision support tools (e.g., Lexicomp/Micromedex) before prescribing or administering medication.